I have a license for a theme, and I need to sell my customised solution

I have a regular license for a theme and I have customised it and now I want to sell my customised solution to multiple users. Should I need a extended license for this or regular license is enough?

You can’t do this with any license.

You will need to buy a new license for each website it is used on/client it is sold to etc.

Thanks Charlie for your time.
Can you tell me, if I do not use license means I will deploy site without license. Is it legal or anything wrong in it?

Not totally sure what you mean but regardless of registering licenses or not, each time you use a theme purchased from envato will require a new license/copy. This is simply part of the terms under which you buy the item.

Aside from this - more often than not authors use different ways to help manage the use of their products

I see, got the point. Thanks bro for your answer.